The present application relates generally to communications networks, and more particularly, to communications network circuits.
Communications networks are widely used for nationwide and worldwide communication of voice, multimedia and/or data. As used herein, communications networks include public communications networks, such as the Public Switched Telephone Network (PSTN), terrestrial and/or satellite cellular networks and/or the Internet.
The Internet is a decentralized network of computers that can communicate with one another via Internet Protocol (IP). The Internet includes the world wide web (web) service facility, which is a client/server-based facility that includes a large number of servers (computers connected to the Internet) on which web pages, applications and/or files reside, as well as clients (web browsers), which interface users with the remote servers. The topology of the web can be described as a network of networks, with providers of network services called Network Service Providers, or NSPs, or Internet Service Providers (ISPs). Servers that provide application-layer services may be referred to as Application Service Providers (ASPs). Sometimes a single service provider provides both functions. As used herein, the term Service Provider (SP) includes, but is not limited to, NSPs, ASPs, and ISPs.
Communications networks include many circuits. A circuit is a physical path between two or more points along which packets can be carried, and consists of one or more wires (or wireless paths) and possibly intermediate switching points. The term “circuit diversity” refers to the use of multiple communications circuits, each having a different physical path. When circuits utilize different physical paths, the cutting of communications lines in one circuit does not cause failure of service in other circuits. Circuit diversity has been considered a best practice for business continuity for the public and private sectors, as well as for the military, particularly since the Sep. 11, 2001 terrorist attacks in New York.
Many entities with critical missions establish service level agreements with SPs to insure circuit diversity in order to guarantee continuity of communications between endpoints. Circuit diversity, however, can change over time for various reasons, including user actions, technician errors, etc. Unfortunately, detecting a change in circuit diversity, particularly by a communications network user, may be difficult. The difficulty in detecting a change in circuit diversity may be exacerbated when a circuit involves multiple SPs.